<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>

        .box {
            width: 300px;
            height: 300px;
            border-radius: 50%;
            margin: 50px auto;
            background-color: #ccc;
            position: relative;
            transform-style: preserve-3d;
        }

        .box .from,
        .box .befor {
            perspective: 400px;
            width: 100%;
            height: 100%;
            border-radius: 50%;
            color: #fff;
            font-size: 30px;
            text-align: center;
            line-height: 300px;
        }

        .box .from {
            position: absolute;
            left: 0;
            top: 0;
            background-color: pink;
            z-index: 4;
        }

        .box:hover {
            transform: rotateY(180deg);
        }

        .box .befor {
            position: absolute;
            left: 0;
            top: 0;
            background-color: purple;
            transform: rotateY(180deg);
        }
    </style>
</head>

<body>
    <div class="box">
        <div class="from">
            他是你的
        </div>
        <div class="befor">
            他永远都是你的
        </div>
    </div>
</body>

</html>